Computer systems generally utilize auxiliary memory storage devices having media on which data can be written and from which data can be read for later use. A direct access storage device (disk drive) incorporating rotating magnetic disks is commonly used for storing data in magnetic form on the disk surfaces. Data is recorded on concentric, radially spaced tracks on the disk surfaces. Magnetic heads are then used to read data from the tracks on the disk surfaces.
FIGS. 1-2 illustrate a method of manufacturing a coil structure associated with a magnetic head, in accordance with the prior art. FIG. 1 illustrates a cross-sectional view of an initial stack 100 with which a prior art coil structure may be manufactured. As shown, the stack 100 includes a first layer 102 including Al2O3 or some other material. Deposited on the first layer 102 is a second layer 104 including Cr or the like. A third layer 106 is deposited on the second layer 104. The third layer 106 is constructed from a conductive material such as Cu or the like.
On the third layer 106 is a fourth layer 108, typically masked photoresist, that is exposed and developed to define a plurality of channels 110. Such channels 110, in turn, define a coil structure. A conductive material 111, such as Cu, is then typically electroplated into the channels. The fourth layer 108 is then wet stripped and the layers 104, 106 ion milled away. An insulation material, like photoresist is introduced between the channels to form a coil structure with a plurality of electrically isolated turns. FIG. 2 illustrates another cross-sectional view of the stack 100 of FIG. 1 after the coil structure has been completed.
A coil structure is thus provided with a certain pitch (Z) and aspect ratio (Y/X). A high aspect ratio is desirable, for a given coil width (X), as the coil resistance decreases with increasing aspect ratio. This reduced coil resistance will lead to reduced device heating during operation (i.e. writing induced protrusion). Traditionally, however, such aspect ratio is limited due to inherent deficiencies with the ion milling process. For example, ion milling may exhibit difficulties in removing the third layer 106 and the second layer 104 if the ratio (Z/X) is too small. Incomplete removal of any conducting layers during ion milling results in electrically shorted coil turns.
There is thus a need for a magnetic head coil structure and a method of manufacturing the same with high aspect ratios without the problems associated with the prior art.